minimally invasive brain surgery @ mayfield

From pin pricks to beams to keyhole incisions, brain surgery is trending smaller

The difference between having a brain aneurysm treated the old way and a new way was aptly described as "the nutcracker" vs. "the TripTik" by a patient of Andrew Ringer, MD. The patient experienced both, and he clearly preferred the TripTik. During the first procedure, Dr. Ringer opened the man’s skull and placed a clip on the threatening aneurysm. In the second procedure, he made a tiny incision in the man’s groin and threaded a catheter up to his brain, then filled the aneurysm with tiny coils.

Reaching the brain through an incision the size of a pin prick is just one example of the direction neurosurgery is taking. A growing number of patients who undergo surgery for aneurysms, stroke, brain tumors, Parkinson’s disease and epilepsy find that they qualify for a minimally invasive treatment that involves 1) endovascular surgery (the "TripTik" through the bloodstream); 2) small "keyhole" incisions in the skull, eyelid or nose; or 3) radiation therapy that involves no incision at all.

This means that, increasingly, neurosurgeons are less apt to open the skull – a procedure called a craniotomy – and are more apt to make repairs by threading catheters, beaming radiation or maneuvering long narrow tools called endoscopes.

"Not all patients qualify for minimally invasive techniques," Dr. Ringer says. "The type and location of the surgical problem, along with the patient’s overall health and age, are factors we must take into consideration. But the growing number of patients who qualify for minimally invasive procedures can reap genuine benefits."

Cerebrovascular disease

In the area of cerebrovascular disease, which includes brain aneurysms, arteriovenous malformations and blocked arteries, neurosurgeons like Ringer are teaming up with interventional radiologists to use endovascular (within-the-artery) procedures to treat disorders of the arteries and veins of the brain by filling them with glue and coils or by neutralizing them with stents, balloons and flow-diverting devices.

"Through several impressive advancements in technology, we are now able to treat these disorders using precise mapping -- like the GPS in your car -- and advanced imaging that make exposure and repair so accurate that we can often avoid the large surgical incisions required in years past," Dr. Ringer says." In fact, many of these disorders can be treated from within the artery or vein itself. A tiny needle stick gives us access to the inside of an artery in the leg, which we then use as a highway to drive the catheter to the arteries in the brain so that we never have to open the patient's head at all."

Skull base tumors

Meanwhile, skull base surgeons have charted new paths to pituitary and meningioma tumors located at the base of the skull. Neurosurgeons and ear, nose and throat surgeons (otolaryngologists) combine to remove these tumors by approaching them through the nose or the roof of the mouth. In one recent case an ear, nose and throat surgeon, inserted a long, tube-like instrument with a light and tiny camera into one nostril and made an incision at the back of the nasal cavity. After reaching the tumor, a neurosurgeon removed it with another long, slender instrument that he inserted into the patient’s other nostril. The entire procedure took 45 minutes.

Some patients with Parkinson’s disease or epilepsy can be effectively treated with deep brain stimulation procedures, which also require only the smallest of incisions.

An electrode is inserted through the tiny opening in the skull and into a movement-controlling area deep within the brain. The lead (wire) is then threaded under the skin and connected to a battery-powered pulse generator, similar to a heart pacemaker, which is implanted near the collarbone.

In the future, Dr. Mandybur says, this powerful tool will allow surgeons to treat other neurologic disorders, including Alzheimer’s disease, eating disorders and psychiatric disorders.

A different type of minimally invasive brain stimulation, called vagus nerve stimulation, can help reduce the frequency of seizures in people with drug-resistant epilepsy. The procedure involves implanting a lead around the vagus nerve in the neck. The lead, connected to a pulse generator implanted under the skin, sends electrical signals that travel along the vagus nerve to the brain.

Tumors and other lesions

Least invasive are radiosurgery and radiotherapy, which require no incision at all. Both involve destroying a tumor or diseased tissue by bombarding it with targeted beams of radiation. Radiosurgery uses high doses of radiation in a single or small number of treatments, while radiotherapy uses lower doses of radiation given in as many as 30 to 35 treatments. Radiation works by damaging the DNA inside cells and making them unable to divide and reproduce, therefUre causing them to die.

The experience can be likened to getting an x-ray. Treatments typically last less than an hour, and there is no discomfort or bleeding. Patients almost always go home the same day.